Interesting stuff! I do have two 810 Happy drives right now, but only one with a V7.x capable firmware. I seem to have completely lost the old firmware from my second board, so it is currently not useable. I plan to buy a V7.x model so that I can have two Happy drives, a long time dream of mine ;)
I'm just a little annoyed that my Tandon drive quit, as I have read that the MPI mechs seem to have trouble with keeping the disk centered and keeping the heads aligned. Given the age of my drives and disks, the last thing I need are drives with design flaws :/